An Enhanced Power Quality Improvement Control Strategy for Grid-Connected Inverters

Aiming to mitigate the issues of serious power quality degradation in distribution networks, this paper proposes an enhanced power quality improvement control strategy for grid-connected inverters. The current reference generation algorithm for the negative sequence and harmonic mitigation is introduced, and a compensation performance assessment method based on the data envelopment analysis is established. Instead of subjectively assigning weights, this method evaluates the relative efficiency of different compensation coefficient combinations based on the real-time power quality measurement. By employing the inverter compensation capacity as the input indicator, and the grid current THD and unbalance factor as the output indicators, the proposed control fully utilizes the actual available capacity of the inverter and realizes a more optimal power quality improvement. Finally, the feasibility and effectiveness of the proposed control strategy are verified in Matlab/Simulink.